Waterjet systems (e.g., abrasive jet systems) are used in precision cutting, shaping, carving, reaming, and other material-processing applications. During operation, waterjet systems typically direct a high-velocity jet of fluid (e.g., liquid water containing particles of abrasive material) toward a workpiece to rapidly erode portions of the workpiece. When compared to other material-processing technologies (e.g., grinding, plasma-cutting, etc.) waterjet processing can have significant advantages. For example, waterjet systems often produce relatively fine and clean cuts, typically without heat-affected zones around the cuts. Waterjet systems also tend to be highly versatile with respect to the material type of the workpiece. The range of materials that can be processed using waterjet systems includes very soft materials (e.g., rubber, foam, leather, and paper) as well as very hard materials (e.g., stone, ceramic, and hardened metal). Furthermore, in many cases, waterjet systems are capable of executing demanding material-processing operations while generating little or no dust, smoke, or other potentially toxic airborne byproducts.
In a typical waterjet system, a pressurizing device (e.g., a direct-drive plunger pump or an intensifier) pressurizes fluid to an ultrahigh pressure, such as a pressure within a range from 30,000 psi to 100,000 psi or more. Some of this pressurized fluid is routed through a cutting head that includes an orifice element having an orifice. The orifice element can be a hard jewel (e.g., a synthetic sapphire, ruby, or diamond) held in a suitable mount, such as a metal plate. Passing through the orifice converts static pressure of the fluid into kinetic energy, which causes the fluid to exit the cutting head as a jet at a high velocity (e.g., a velocity of up to 2,500 feet-per-second or more) and impact a workpiece. In some cases, an abrasive material (e.g., garnet or silica) is entrained within the formed jet at a mixing chamber within the cutting head. Alternatively, and less typically, the fluid can already contain entrained abrasive material before it reaches the cutting head. The use of abrasive material tends to facilitate erosive cutting, particularly for relatively dense workpiece materials. After eroding through a portion of the workpiece, the jet typically is dispersed in a fluid pool held within a catcher positioned below the workpiece, thereby allowing the kinetic energy of the jet to dissipate. A jig including spaced-apart slats can be used to support the workpiece over the catcher. The jig, the cutting head, the workpiece, or a combination thereof can be movable under computer and/or robotic control such that complex processing instructions can be executed automatically.
Conventionally, in the context of waterjet processing, using a feed fluid with relatively high hardness and/or a relatively high concentration of total dissolved solids (“TDS”) is considered to be undesirable. This practice, for example, is thought to increase mineral precipitation (e.g., scaling) on surfaces within waterjet systems. Ultrahigh pressures may exacerbate this problem by decreasing the solubility of certain dissolved solids. It is thought that, over time, flakes of mineral precipitate may clog or otherwise damage fluidic components of waterjet systems. Accordingly, some manufacturers of waterjet systems recommend using municipal water as a feed fluid and periodically testing the hardness and the TDS concentration of the water. If the hardness and/or the TDS concentration of the water is too high, softening by ion exchange and/or partial deionization by ion exchange or reverse osmosis may be recommended. Manufacturers of waterjet systems do not recommend complete or near-complete deionization of feed fluids because this is known to cause the feed fluids to become corrosive. For example, instead of depositing mineral precipitates on surfaces within waterjet systems, completely or nearly-completely deionized feed fluids may tend to leach material (e.g., metal) from these surfaces. In addition to controlling the hardness and the TDS concentration of feed fluids, filtering feed fluids with 0.4 micron bag filters to trap large particles upstream from pressurizing devices of waterjet systems is also known. Thus, conventional approaches to treating feed fluids in the context of waterjet processing focus on the hardness of the feed fluids, the TDS concentration of the feed fluids, and the presence of large particles in the feed fluids. As discussed below, these approaches may be less effective, less efficient, and/or have other disadvantages relative to approaches in accordance with embodiments of the present technology.
Independent of the treatment of feed fluids, byproduct fluids in the context of waterjet processing may have characteristics that present technical challenges. When a jet including abrasive material disperses in a fluid pool, fluid and particles of abrasive material within the jet become incorporated into the fluid pool. In at least some cases, particles of workpiece material liberated from processed workpieces are also incorporated into the fluid pool. Eventually, the particles of abrasive material and/or workpiece material accumulate in the fluid pool to unacceptable levels. Draining and disposing of the fluid pool is wasteful and can be costly when environmental issues preclude direct disposal into municipal sewer lines. Environmental issues are common, for example, when waterjet systems are used to process workpieces made of toxic materials. Some approaches to treating byproduct fluids in the context of waterjet processing for disposal or reuse are known. These approaches may rely heavily on filtration. As with conventional approaches to treating feed fluids, conventional approaches to treating byproduct fluids in the context of waterjet processing may be less effective, less efficient, and/or have other disadvantages relative to approaches in accordance with embodiments of the present technology.